With the development of such electronic devices as tablet computers and smart phones, peripheral devices mating with such electronic devices grow more and more plentiful. A keyboard, as an input tool, is a type of commonly used electronic device.
For user's convenience during use of such a keyboard, the keyboard is generally provided with a bracket apparatus to place such an electronic device as tablet computer and smart phone. However, the bracket apparatus generally needs to be opened manually; or during bouncing of the bracket apparatus, such problems as inaccurate positioning and unsmooth positioning cause inconvenience to the use, thereby greatly affecting user experience.